Alcohol hand sanitizers are widely accepted and used in the hospital and healthcare sectors. There are disadvantages in alcohol-based sanitizers. Thus, there is a lack of user comfortability and antimicrobial performance, especially long-term antimicrobial performance, is poor. There is no residual activity. Hands will be contaminated right after alcohol has evaporated, and the thickening agent used in the sanitizers will form a residual layer on the sanitized object, such as the user's hands, and offers a good substrate for microbial growth. Also alcohol itself can cause drying and irritation of skin. Alcohol is not effective against all known pathogens.
Patent publication WO 2012018888 describes an antiseptic liquid formulation, a method for its use, and a method for preparing the formulation. It contains a mixture of EDTA chelated silver ion and polyquaternium-69 polymer, which is said to bond chelated silver ions on the skin, and improve long term performance.
Silver based sanitizers suffer from stability problems, causing discoloration and performance issues. Also colloidal and particle based silver sanitizers can agglomerate and cause concentration differences.
Antimicrobial compositions are also described in JP 3406970, WO 2013/026961, WO 2012/144476 and US 2009/0246258.
None of the earlier publications discloses foams or foamable compositions which are stable and which exhibit an extended antimicrobial effect.